The present application relates to an indirect conversion detector array of a radiation system. It finds particular application in medical, security, and/or industrial fields, where radiation imaging systems are used to identify/view interior aspects of an object under examination.
Today, radiation systems such as computed tomography (CT) systems, single-photon emission computed tomography (SPECT) systems, digital projection systems, and/or line-scan systems, for example, are useful to provide information, or images, of interior aspects of an object under examination. The object is exposed to rays of radiation photons (e.g., x-ray photons, gamma ray photons, etc.) and radiation photons traversing the object are detected by a detector array positioned substantially diametrically opposite a radiation source relative to the object. A degree to which the radiation photons are attenuated by the object (e.g., absorbed, scattered, etc.) is measured to determine one or more properties of the object, or rather aspects of the object. For example, highly dense aspects of the object typically attenuate more radiation than less dense aspects, and thus an aspect having a higher density, such as a bone or metal, for example, may be apparent when surrounded by less dense aspects, such as tissue or clothing.
Detector arrays comprise a plurality of detector cells, respectively configured to detect radiation impinging a pre-defined portion of the detector array. The detector cells are configured to directly or indirectly convert radiation photons into electrical charge. Direct conversion detector cells are configured to convert the radiation photons directly into electrical charge using a photoconductor (e.g., amorphous selenium). Indirect conversion detector cell are configured to convert the radiation photons into light using a scintillator and to convert the light into electrical charge using a photodetector, such as a photodiode. In a detector array comprising indirect conversion detector cells, conventional detector cells include one or more scintillators. The one or more scintillators are arranged such that the radiation photons impinge a detection surface of the detector cells at a perpendicular angle. In this way, a thickness of the one or more scintillators should be sufficient to allow for optical photons to exit the scintillator while not being so thick to mitigate excessive cross-talk between adjacent detector cells.